Hi Mauro, > Ramesh Shanmugasundaram <ramesh.shanmugasundaram@xxxxxxxxxxxxxx> escreveu: > > > Hi Mauro, > > > > Thanks for the clarifications. > > > > > Ramesh Shanmugasundaram <ramesh.shanmugasundaram@xxxxxxxxxxxxxx> > escreveu: > > > > > > > Hi Maintainers, All, > > > > > > > > Renesas R-Car SoCs have Digital Radio Interface (DRIF) controllers. > > > > They are receive only SPI slave modules that support I2S format. > > > > The targeted application of these controllers is SDR. [...] > > > If, for performance issues, it would require a faster I/O, then such > > > tuner app should be converted to be a Kernel driver. Usually, it is > > > not hard to convert those drivers to Kernelspace, as typically it is > > > just a bunch of registers that should be set to make it to tune into > > > an specific frequency and to adjust the tuner filters to the desired > > > bandwidth and modulation type, in order to improve noise rejection. > > > > Yes, this is possible. However, this is Tuner chip vendor's decision > (NDA, license issues etc.) and it is not in our control. > > True, but an independent tuner driver very likely can be written with very > little effort. All it requires is to monitor the traffic at the I2C bus > and to write a driver that reproduces it, identifying what part of the I2C > messages contain the frequency and enable/disable the filters. Yes, this is possible. > > We have several such drivers in the Kernel, and that's the procedure used > when the chipset vendor doesn't see the value of having his chipset used > by a Linux-based device. > > > As mentioned above, we can have the main SDR (DRIF) driver code to > direct tuner subdev if present. However, when we want to upstream the DRIF > driver we may not have a real Tuner driver/device to get the compliance > test results. Should we run the compliance tests with a dummy stubbed > tuner subdev? > > No, an upstream requirement is to have everything tested on real hardware. > What I recommend you is to either convince the tuner provider to send > upstream a driver (or allow you to do so) or to switch to some other > vendor whose driver is already in the Kernel or sees the value of having > his chipset used on Linux. Yep, that is a clear mandate. We shall talk to Tuner vendor and decide accordingly. Thanks for your time and inputs, Ramesh
